For electric vehicle (EV) owners, understanding the health of their battery is crucial. Battery State of Health (SOH) is a key metric that indicates the battery’s current capacity compared to its original capacity. Dealers play a significant role in assessing battery health, especially when warranty claims are involved. However, it’s important for EV owners to be aware of potential issues in dealer diagnostic procedures and how to ensure accurate readings, which may be facilitated by tools like an Electrical Car Scanner.
Dealer Diagnostic Practices and Potential Pitfalls
Some EV owners have reported that dealerships may sometimes dismiss battery health readings that are not obtained using the KIA Diagnostic Unit (KDU) for Kia vehicles, or similar manufacturer-specific tools for other brands. Furthermore, there’s a tendency among some dealers to believe that Battery Management System (BMS) updates can magically improve the battery’s health. In reality, applying these updates before properly assessing the battery’s SOH can actually lead to inaccurate readings. This is because BMS updates can reset the system to default values, requiring several charge cycles before valid battery data is available again. Consequently, after such updates, dealers might obtain artificially inflated SOH readings, often well above 70%, potentially masking underlying battery degradation issues. This practice can prevent owners from receiving necessary battery replacements under warranty when the SOH is genuinely below the threshold.
Ensuring Accurate SOH Readings: The PS 548 Procedure
To counter potential misdiagnoses, especially for Kia EVs, owners can proactively guide their dealers towards accurate battery health assessments. One effective approach is to reference and provide a copy of PS 548, a specific procedure designed to ensure correct SOH readings. When visiting a dealer, request that they perform the procedure outlined in PS 548 precisely as instructed. It’s crucial to emphasize that applying any BMS updates before reading the BMS data will prevent an accurate SOH reading. Highlighting the relevant sections of the PS 548 document and drawing the dealer’s attention to these critical points can further reinforce the importance of following the correct procedure.
If, after following the PS 548 procedure correctly, the SOH reading is below 70%, this outcome should prompt the dealership to report the findings to KIA Corporate, potentially leading to a battery replacement under warranty. This proactive approach ensures that dealers rely on accurate diagnostic methods rather than potentially misleading update-driven readings.
Calculating SOH Manually: A Practical Guide for EV Owners
Beyond dealer diagnostics, EV owners can also independently estimate their battery SOH using a straightforward calculation method. This can serve as a valuable cross-reference to dealer readings and provide ongoing insight into battery health. Here’s how to calculate your SOH manually:
- Full Charge and Reset: Begin by fully charging your EV battery to 100%. After charging is complete, reset your car’s m/kWh meter (mileage per kilowatt-hour). This meter usually displays “–” upon reset. Record the odometer reading (mileage) at this point and note the battery percentage if it’s not exactly 100%.
- Discharge and Record: Drive your EV until you need to recharge. Before commencing the next charge, record the new odometer reading and the battery percentage. Also, note the m/kWh reading accumulated since the reset.
- Calculate kWh Consumed: Determine the difference between the two odometer readings to find the miles driven. Divide this mileage difference by the m/kWh value to calculate the kilowatt-hours (kWh) of energy consumed during that driving period.
- Calculate Percentage Difference: Find the difference between the initial and final battery percentages. Convert this percentage difference into a decimal fraction by multiplying it by 0.01.
- Estimate 100% Capacity: Divide the kWh consumed (from step 3) by the decimal fraction obtained in step 4. This result approximates your battery’s current kWh capacity at a 100% charge.
- Determine SOH Percentage: Divide the estimated 100% capacity (from step 5) by the nominal battery size of your EV model (e.g., 27, 30, 39.2, 64 kWh, or other value depending on your specific model). Multiply this result by 100 to express the SOH as a percentage.
This manual calculation method offers a practical way for EV owners to monitor their battery health independently. While tools like electrical car scanners offer more advanced diagnostics, this method provides a valuable and accessible alternative for estimating SOH and verifying dealer assessments. It’s worth noting that this manual method has been tested against more sophisticated diagnostic tools and has shown to provide reasonably close agreement, making it a reliable option for EV owners seeking to understand their battery’s condition.
